Project Case Study

Red Line Mass Transit, Bangkok, Thailand


State Railway of Thailand (SRT)




Expected daily commuters

Customer Challenge

Like cities worldwide, Bangkok needs a safe, efficient and cost-effective solution to get its 10 million people moving. With traffic congestion and air pollution major problems – 75% of public transport in the city currently depends on buses – State Railway of Thailand (SRT) is keen to create a mass rapid transit system that will encourage a shift from road to rail.

SRT began constructing its new Red Line suburban rail system back in January 2009. The system consists of two lines: the 26km Dark Red line linking the northern and southern parts of Bangkok, and the 15km Light Red service linking east and west. Parts of the lines passing through inner-city areas are elevated and there are four track and double track sections. The new Bang Sue Central Station – a ‘mega-station’ replacing the century-old Hua Lamphong Station – will act as a connecting hub for the lines. Once complete, it will be the biggest station in South East Asia.

We had already worked on parts of the city’s mass rapid transit system run by Bangkok Mass Rapid Transport Authority (metro), including the Purple Line and Green Line South that were completed in 2016 and 2017, the Green Line North which is due to fully open at the end of 2020 and the Orange Line East, currently under construction.

When SRT was looking for solutions for its Red Line that combined ease and speed of installation with durability, reliability and long-term performance, Pandrol was the natural fit.

Pandrol Solution

We provided our SRS and DRS fastening solutions for elevated sections of the Red Line, with Pandrol e-Clip used for ballasted sections. Like all of our fastening systems, these are an evolution of time-tested technologies, renowned for their safety and reliability. The SRS and DRS fastenings bring particular benefits in terms of insulation and noise and vibration mitigation, making them ideal for use in the city-centre setting. On ballasted track, our under-sleeper pads were used to reduce vibration levels in sensitive areas.

Our PLA one-shot crucible aluminothermic welding kits were used to weld the Red Line’s long rail strings together, including for wide-gap welding. The solution provided is of the highest quality in South East Asia. The welding team from Worksop team assisted with training in the use of the technology, including instruction and demonstration of products and equipment, and welder certification.

To support the Red Line’s European Train Control System (ETCS) signalling, we supplied Vortok clamp beams. This non-intrusive balise transponder mounting system uses the rail fastenings to hold the beam in track, eliminating the need to drill sleepers or dig out ballast. As a result, installation typically takes less than five minutes per balise. Once installed, the beam is completely insulated, vibration resistant, strong and durable, ensuring a long life on the Red Line.

For the Red Line depot, we supplied and designed the retractable rigid catenary system for the electrification. Adapted, reliable and secure, this will allow work to take place in safety and ease maintenance operations on trains. In addition, the Pandrol FR fastening system was used in the depot – an elastic fastening that brings benefits in terms of vibration attenuation, creep resistance and electrical insulation. The assembly is designed for long life, can be fully dismantled for inspection and maintenance, and all parts are replaceable.

Clamp beam

This non-intrusive balise transponder mounting system uses the rail fastenings to hold the beam in track, eliminating the need to drill sleepers or dig out ballast.

Clamp Beam


The Red Line – along with Bang Sue Central Station – is on track to open in 2021. It will be used by both Red Line commuter trains and long-distance services, and is expected to carry in the region of 208,000 commuters a day.

Three extensions for the Red Line are now being planned, along with a three airports high-speed link that will also run through Bang Sue Central.

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